1. The Field of the Invention
The invention is in the field of raised access flooring systems, which are typically used to provide space between a floor and a subfloor to provide air duct or to provide a space in which conduits, and electrical boxes may be located. The present invention incorporates a space frame like structure configured to provide a raised access flooring system with modules that are removable and interchangeable.
2. The Background Art
With the advent of computers and word processors, the need for raised access flooring systems has escalated. It has been found to be very economical to provide a flooring system in new construction, and even to modify old construction, wherein ready access is available to conduits, ducts, utilities, and other items so that additions to, and changes in locations of, electrical outlets, computer cable outlets, heating and cooling outlets, and the like can be readily made without major structural changes. This is of particular importance in today's economic environment wherein the cost of floor space is exceedingly high, thus leading to constant remodeling in order to make better use of available space.
Additionally, it has been found prudent to provide a flooring system wherein load-bearing capability can be modified to accommodate new equipment, or even one where different sections can have different load-bearing capabilities.
Additionally, for applications involving clean rooms, a raised access flooring system having a multiplicity of perforations in the floor above a subfloor provides a convenient means for continuous air circulation to remove unwanted contaminating particles. A flooring system such as this is also very beneficial in computer rooms wherein it is necessary to provide adequate and even cooling throughout the room.
Raised access flooring systems conventionally employ a multitude of floor modules supported on pedestals above a subfloor with the floor modules normally having a square configuration and arranged in a grid with respect to each other. A typical module is two feet square.
Prior art floor modules typically employ a thin flat plate stiffened by a ribbed grating, both being configured as one piece, as the flooring member. The module is supported at the corners by pedestals that interface the bottom of the grating. The grating must have sufficient strength to accommodate the expected floor loads without allowing rupturing or excessive bending of the plate beyond an industry-specified limit. This requirement dictates the dimensions of the thickness and depth of the ribs supporting the grating which, of course, is also dependent on the material used.
When an occasion arises wherein the load-bearing capability of some section of the floor must be increased, such as to accommodate a new piece of equipment, then the load-bearing capacity of the modules in that section must be increased. From an economics of material standpoint, this is effected by increasing the depth of the ribs in the grating. However, this could lead to a requirement to increase the thickness of all floor sections in order to maintain an even floor surface. This, of course, results in an expensive modification, and also a greater load on the subfloor.
For clean room and computer room applications perforations are sometimes formed in the flat plate to permit airflow therethrough, communicating with the space under the module.
Access ports must be provided in certain modules in order to provide passageways for conduits, ducts, cables, wiring, and other like utility items, to pass therethrough. Some modules require sawing to effect such access ports. This is a costly, time-consuming operation. Furthermore, such access ports inevitably reduce the load-bearing capability of the module, thus minimizing the size of the access ports that can be incorporated and/or further increasing the required stiffening of the plate.
Another problem with prior art modules relates to the increased depth of the module over and above that required to provide access space for utility wiring and the ducts formed between the floor and subfloor. Since prior art modules are supported from the bottom of the grating the access space plus the depth of the ribs in the grating dictate the total dimension that raises the floor above the subfloor. This, of course, reduces the floor-to-ceiling height of a room, an undesirable result.